The disclosure relates to a micromechanical solid-electrolyte sensor device and to a corresponding production method.
Solid-electrolyte gas sensors are known in the prior art, for example as an oxygen sensor in the form of a lambda probe. A lambda probe formed as a Nernst probe measures the voltage of a solid electrolyte, zirconium dioxide being used as a membrane. The property of zirconium dioxide that it can electrolytically transport oxygen ions at elevated temperature (typically 650° C. in the case of ceramic probes), so that a measurable voltage is formed, is utilized in this case.
DE 199 41 051 A1 discloses a gas sensor which is formed as a broadband lambda probe, which comprises a ceramic solid-electrolyte base and a plurality of electrodes that are applied in chambers and on the outer side of the solid electrolyte.
As the technology for such known solid-electrolyte sensor devices, the ceramic thick-film technology is used, which only permits relatively large minimum dimensions both for the structural widths (typically more than 30 μm) and for the layer thicknesses (typically more than 10 μm). By combining a plurality of cells, besides oxygen sensors it is also possible to produce other types of gas sensors, for example for nitrogen oxides, but these are expensive and require complicated evaluation electronics.